Would like advice have 5 yr old Lab and 2 yr old BT both entire. Are kennelled together and are at work together with me all day. Usually get on well but BT has now started to assert himself, and has resulted in growling, and staring each other down. Have had minor scuffles without drawing bloodI usually break the stare between them and distract with other stuff. Does anyone have any better ideas?
Also Lab is very protective of me and will growl and bark at people visiting the office . If we are walking he will run straight upto people barking and behaving like a yob.Can be very intimadating for the person on the receiving end of this behaviour. He is actually my partners dog and does resond with total manners around him, but shows  no obedience with me. !!Any advice greatly appreciated.

What is the BT a Border Terrier a Bull Terrier or something else?  could make quite a bit of difference to the replies and solutions suggested

Sorry Border Terrier

Well that is a big size difference, so sorting it out themselves is not a realistic or desirable option.

It looks like training is needed for both boys.  This will make them both look to you more as a leader and will help you with managing them, or may even mean they see no need for leadership disputes as you are clearly very much in charge.

Dogs need to feel they live in a structured society with clear leadership.  If they are unclear that this is you then one of them will feel compelled to be one, even if they are not suited to the role.

So to start with I would get them both to training classes and doing short training sessions with you at home to underline your role.  Also consider in which situations they are having scraps, is it food, toys, your attention etc.  You can then ensure these situations are minimised, and if need be install a baby gate so they are not left alone without supervision.

not got enough experience myself to offer any solution, hpoefully someone will soon, but i have  to say i dont think you should be letting him run up to people, who i assume are strangers, barking.That could be very frightening and is easilly cured by using a lead.

morgan is right.  And, every time he's allowed to practise the behaviour (i.e. run up to people barking) it reinforces it for him and makes it harder to retrain.  In that situation, for now, I'd be putting him on lead whenever you see another person, and rewarding heavily for good behaviour.